This evening I finally got fed up with T-Mobile taking so long to update my G-1 Android phone to a newer version of Android, so I took it upon myself to do the dirty work. Version 1.6 was the last that T-Mobile made available as an update, but new phones from Verizon, Google and even T-Mobile are up to version 2.2. (Of course, by doing this I have made myself persona non grata to T-Mobile, invalidating any warranty that might be left.)
I followed the instructions found here, studied them very carefully and downloaded all of the files required before I started. (They even have videos that run through the whole procedure.) Once I got started it took less than a half hour, and now my phone as a new lease on life. For the record, I used the mod from Cyanogen, which took the phone to 2.1. It all seems to work just fine. I was just hoping not to end up with a useless brick.